Spiral springs

Coil spring variants

A wide range of applications

• Flat spiral springs: Also known as watch springs, these are made from round or shaped metal wire, often wound in an Archimedean spiral around a drum or axle. It stores energy by twisting between the hub (fixed) and the band (mobile). The flat spiral spring is often found in precision applications.
• The mainspring: Also known as the barrel spring, this uses a flat ribbon that is longer and/or stronger than the flat spiral spring. It is often wound in a cylindrical housing (barrel). It stores or releases energy by continuously rotating the drum and can generate high torque over a long period.
• The constant force spring: This is made from a pre-stressed strip, wound in contiguous coils, which unwinds without any noticeable variation in force. It therefore provides a constant force over the entire unwound length. It can be used for traction, return, or to generate linear or rotary movement.
• The volute spring: This is made from wire or metal strip wound into a conical spiral, like a snail shell. The conical (rather than flat) turns partially interlock when compressed. It generates a strong restoring force over a short distance. The volute spring is not a torsion spring like other spiral springs.